<template>
  <div class="q-pa-md">
    <t-table
      flat
      bordered
      ref="tableRef"
      title="Treats"
      :rows="rows"
      :columns="columns"
      row-key="name"
      :selected-rows-label="getSelectedString"
      selection="multiple"
      :selected="selected"
      @selection="onSelection"
    />

    <div class="q-mt-md"> Selected: {{ JSON.stringify(selected) }} </div>
  </div>
</template>

<script>
  import { useQuasar } from '@teld/q-components';
  import { ref } from 'vue';

  const columns = [
    {
      name: 'desc',
      required: true,
      label: 'Dessert (100g serving)',
      align: 'left',
      field: row => row.name,
      format: val => `${val}`,
      sortable: true,
    },
    {
      name: 'calories',
      align: 'center',
      label: 'Calories',
      field: 'calories',
      sortable: true,
    },
    { name: 'fat', label: 'Fat (g)', field: 'fat', sortable: true },
    { name: 'carbs', label: 'Carbs (g)', field: 'carbs' },
    { name: 'protein', label: 'Protein (g)', field: 'protein' },
    { name: 'sodium', label: 'Sodium (mg)', field: 'sodium' },
    {
      name: 'calcium',
      label: 'Calcium (%)',
      field: 'calcium',
      sortable: true,
      sort: (a, b) => parseInt(a, 10) - parseInt(b, 10),
    },
    {
      name: 'iron',
      label: 'Iron (%)',
      field: 'iron',
      sortable: true,
      sort: (a, b) => parseInt(a, 10) - parseInt(b, 10),
    },
  ];

  const rows = [
    {
      name: 'Frozen Yogurt',
      calories: 159,
      fat: 6.0,
      carbs: 24,
      protein: 4.0,
      sodium: 87,
      calcium: '14%',
      iron: '1%',
    },
    {
      name: 'Ice cream sandwich',
      calories: 237,
      fat: 9.0,
      carbs: 37,
      protein: 4.3,
      sodium: 129,
      calcium: '8%',
      iron: '1%',
    },
    {
      name: 'Eclair',
      calories: 262,
      fat: 16.0,
      carbs: 23,
      protein: 6.0,
      sodium: 337,
      calcium: '6%',
      iron: '7%',
    },
    {
      name: 'Cupcake',
      calories: 305,
      fat: 3.7,
      carbs: 67,
      protein: 4.3,
      sodium: 413,
      calcium: '3%',
      iron: '8%',
    },
    {
      name: 'Gingerbread',
      calories: 356,
      fat: 16.0,
      carbs: 49,
      protein: 3.9,
      sodium: 327,
      calcium: '7%',
      iron: '16%',
    },
    {
      name: 'Jelly bean',
      calories: 375,
      fat: 0.0,
      carbs: 94,
      protein: 0.0,
      sodium: 50,
      calcium: '0%',
      iron: '0%',
    },
    {
      name: 'Lollipop',
      calories: 392,
      fat: 0.2,
      carbs: 98,
      protein: 0,
      sodium: 38,
      calcium: '0%',
      iron: '2%',
    },
    {
      name: 'Honeycomb',
      calories: 408,
      fat: 3.2,
      carbs: 87,
      protein: 6.5,
      sodium: 562,
      calcium: '0%',
      iron: '45%',
    },
    {
      name: 'Donut',
      calories: 452,
      fat: 25.0,
      carbs: 51,
      protein: 4.9,
      sodium: 326,
      calcium: '2%',
      iron: '22%',
    },
    {
      name: 'KitKat',
      calories: 518,
      fat: 26.0,
      carbs: 65,
      protein: 7,
      sodium: 54,
      calcium: '12%',
      iron: '6%',
    },
  ];

  export default {
    setup() {
      const $q = useQuasar();

      const selected = ref([]);
      const lastIndex = ref(null);
      const tableRef = ref(null);

      return {
        selected,
        lastIndex,
        tableRef,

        columns,
        rows,

        getSelectedString() {
          return selected.value.length === 0
            ? ''
            : `${selected.value.length} record${
                selected.value.length > 1 ? 's' : ''
              } selected of ${rows.length}`;
        },

        onSelection({ rows, added, evt }) {
          if (rows.length === 0 || tableRef.value === void 0) {
            return;
          }

          const row = rows[0];
          const filteredSortedRows = tableRef.value.filteredSortedRows;
          const rowIndex = filteredSortedRows.indexOf(row);
          const localLastIndex = lastIndex.value;

          lastIndex.value = rowIndex;
          document.getSelection().removeAllRanges();

          if ($q.platform.is.mobile === true) {
            evt = { ctrlKey: true };
          } else if (
            evt !== Object(evt) ||
            (evt.shiftKey !== true && evt.ctrlKey !== true)
          ) {
            selected.value = added === true ? rows : [];
            return;
          }

          const operateSelection =
            added === true
              ? selRow => {
                  const selectedIndex = selected.value.indexOf(selRow);
                  if (selectedIndex === -1) {
                    selected.value = selected.value.concat(selRow);
                  }
                }
              : selRow => {
                  const selectedIndex = selected.value.indexOf(selRow);
                  if (selectedIndex > -1) {
                    selected.value = selected.value
                      .slice(0, selectedIndex)
                      .concat(selected.value.slice(selectedIndex + 1));
                  }
                };

          if (localLastIndex === null || evt.shiftKey !== true) {
            operateSelection(row);
            return;
          }

          const from = localLastIndex < rowIndex ? localLastIndex : rowIndex;
          const to = localLastIndex < rowIndex ? rowIndex : localLastIndex;
          for (let i = from; i <= to; i += 1) {
            operateSelection(filteredSortedRows[i]);
          }
        },
      };
    },
  };
</script>
